Take-up mechanism



-May13,1947. 'R K HOHMANN I 2,420,535

TAKE-UPV MECHANISM Filed Jan. 15,v 1945 f INVENTO /CHA /fo h. HUHMANN)Jl a. MV1/d ATTORNEY Patented May 13, 1947 TAKE-UP MECHANISM Richard K.Hohmann, Jamaica, N. Y., assigner to White Sewing Machine Corporation,YCleve*- kland, Ohio, a corporation of Delawarek Application January 15,1945, Serial No. 572,930

2 claims. l

The present invention relates to sewing machines, and particularly todomestic sewing machines of the type comprising side by side needle andpresser bars, a take-up mechanism, and needle bar and take-up mechanismoperating parts, al mounted in the hollow head portion of a sewingmachine frame, and the general object of the present invention is toimprove sewing machines of th'e type specified in respect to the formand disposition, or relative arrangement, of the above mentioned sewingmachine elements.

My prior Patent 1,393,127 of October 1l, 1921, discloses a practicallydesirable yand commercially successful combination of needle bar,take-up mechanism and operating connection parts through which said barand mechanism are connected to a common drive shaft transverse to theneedle bar, the take-up mechanism of said combination including anoscillating arm carried by a rock shaft. The latter is parallel' to thedrive shaft and which is displaced in the same direction from theadjacent end' of said sh'aft and from each of said bars, and intersectsthe plane including the axes of both bars.

A specic object of the present invention is to improve said combinationso as to permit the length, weight and inerti-a of the rock shaft to bereduced, and so as to permit the use of the improved combination insewing machines in which thev relative arrangement of thev two bars andthe rock shaft prevents th'e latter from extending to said plane.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, its advantages, and specific objects attained by its use,

reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described a preferred embodimentof the invention.

Of the drawings:

Fig. 1 is a front end elevation of the head portion of a sewing machineframe with the cover plate removed;

Fig. 2 is a view taken similarly to Fig. 1 but showing parts indifferent positions; and

Fig. 3 is a section on the line 3-3 of Fig. 2.

In the construction shown in the drawings, A is the hollow head portionof a sewing machine frame, and A' is the removable cover plate normallyclosing the open front end of the chamber B in the head A. The head A isprovided with separate upper and lower bearings for a needle (Cl.IRQ-241) bar C and a presser bar D. As shown, the presser bar maybemanually raised and lowered by a lever D of conventional form. The barsC` and D are adjacent but spaced away from one another and' haveY theirparallei axes transverse to the axis of the rotating drive shaft E whichgives the needle bar its up and down movements, and which also givesoscillating movements to a takeup arm F; The latterv is carried byr arock shaft G parallel to the drive shaft E and displaced therefrom tothe rear, or left as seen in Figs. 1, 2 and 3'. Advantageously and asshown, the rock shaft G is hollow and isv mounted on a stationary shaftG having its end remote from the cover plate A secured to the head A.

The end of the driving shaft extendingv into the chamber B carries acrank disc H cut away for balancing and weight reducing purposes'. Atits side facing the cover plate A', the disc H carries a crank pin I,the free end of which is secured toY and carries an arm J spaced awayfrom the front end of the disc H at its end remote` from the crank pin`I. The arm J carries a crank pin K which is parallel to the shaft E andlaterally displaced from the latter. The parts H, I, J and K,collectively form a crank shaft portion of the shaft E including crankshaft portions, formed by the pins IV and K, which are parallel to themain. shaft E and which have their respective axes laterally displacedin different. directions, and for different distances from th'e axis` ofthe shaft E.

The crank pin K gives up and down movements to the needle bar C througha link L pivotally connected at its upper end to said crank pin J andhaving its lower end pivotally connected to, the needle bar by a pivotM. The crank pin I gives oscillating movements to the rock shaft Gthrough an arm O secured to the rock shaft G, and a block P journalledon the crank pin I, and formed with a passage transverse to and at oneside of said pin through which the arm O extends and in which said armis longitudinally movable.

Insofar as above described, the needle bar C, take-up arm F, and theiroperative connections to the common drive shaft E, do not differ fromcorresponding parts shown in my above mentioned prior patent. Theimproved construction disclosed herein differs from the constructiondisclosed in the prior patent, however, in two practically importantrespects, namely, in respect to the length ci the rock shaft G, and inrespect to the form of the take-up arm F and its disposition relative tothe needle bar C and presser bar D.

In my prior patent, the rock shaft giving the take-up arm itsoscillating movements, has its end remote from the cover plate A'connected to and located relatively to the corresponding crank shaftportion of the driving shaft substantially as shown in the accompanyingdrawings. In the prior construction, however, the rock shaft iselongated so that it extends to the opposite side of the needle bar andpresser bar from that at which the operating connection between the rockshaft and driving shaft is located. In said prior patent, the take-uparm is substantially straight and at the opposite side of both needlebar and the presser bar from the operating connection so thatthe shaftlies wholly to the Side of the` presser bar remote from the cover plateA', and the take-up arm F is offset so that its portion connected to andadjacent the rock shaft lies at the rear of the presser bar while itsfree end portion is in front of the needle bar, and an intermediateconnection portion F extending between the two bars. With the take-uparm F shaped as described, the shortening of the rock shaft G does notprevent the free end of the arm from moving the thread passage formed init along the same path of movement which has been shown to be desirablein the extensive commercial use of the construction of my prior patent.The reduction in the length, weight and inertia of the rock shaft ispractically desirable from the construction and operation standpoints,and reduces the tendency to and risk of objectionable vibration.

Moreover, as is clearly shown in Fig. 3, the shortening of the rockshaft permits the latter to be located so that if longer it would extendinto engagement with the presser bar. The shortening of the shaft thuspermits the type of take-up mechanism shown in said prior patent' to beemployed in sewing machines of a design now in commercial use, in whichthe needle bar and presser bar are spaced too widely apart to permit therock shaft of the take-up mechanism to extend past the presser bar as itdoes in said prior patent, unless changes are made in the relativeproportions of the take-up mechanism which would be objectionable fromthe construe.. tion standpoint, and because they would tend to produceobjectionable oscillation.

While in accordance with the provisions of the statutes, I haveillustrated and described the best form of embodiment of my inventionnow known to me, it, will be apparent to those skilled in the art thatchanges may be made in the form of the apparatus disclosed withoutdeparting from the spirit of my invention as set forth in the appendedclaims, and that in some cases certain features of my invention may beused to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. The combination with a sewing machine needle bar and a rotating driveshaft extending transversely to a plane which is parallel to the axisof, and intersects said bar and comprising two crank portions at oneside of and at different distances from said plane and a connectionbetween one of said crank portions and said bar through which therotating drive shaft reciprocates said bar, of a rock shaft parallel toand laterally displaced from said drive shaft and at said one side ofsaid plane, a connection between said rock shaft and the second of saidcrank portions through which said rotating shaft oscillates said rockshaft and a take up arm secured at one end to said rock shaft and havingthread engaging means adjacent its other end and having its portionadjacent the rock shaft at said one side of said plane and having itsend portion remote from said rock shaft at the opposite side of saidplane and extending past said bar and having an intermediate portionextending through said plane.

2. A combination as specified in claim 1, comprising a presser barparallel to said needle bar and in position to be intersected by theportion of said plane nearest to said rock shaft and in which the saidintermediate portion of said take up arm extends between said bars.

RICHARD K. HOHMANN.

REFERENCES CITED l UNITED STATES PATENTS Name Date Hohmann Oct. 11, 1921Number

